This invention relates to a reversible refrigerant heat pump system wherein a pair of volumes are provided to function alternatively as a muffler oil separator when in the path of high pressure discharge refrigerant gas and as an accumulator liquid refrigerant separator when in the path of low pressure suction refrigerant gas.
In some conventional reversible refrigerant heat pump systems, a suction accumulator is provided in the suction line between the compressor and the reversing valve. In this arrangement, the accumulator is permanently arranged in the suction line between the compressor suction inlet and the system reversing valve. This provides a volume that functions as an accumulator in both the heating and cooling cycle; however, it does not provide for oil separation and muffling in the high pressure discharge side of the system. The gaseous refrigerant discharged from the compressor contains lubricating oil dispersed therein in the form of fine particles. The oil, together with the gaseous refrigerant, is fed to the refrigeration system heat exchangers. Some of this oil will remain in the system, causing a reduction in heat transfer rate of the heat exchangers and in some situations may result in the volume of oil in the compressor oil sump to be inadequate to effectively lubricate the compressor bearings. To prevent this, means must be provided for separating entrained oil from the discharged refrigerant gas before it travels to the system heat exchangers in a manner that allows the entrained oil to be returned to the compressor oil sump.